emarknot

a true 4 cam motor has 4 dedicated cams. we have a master/slave.......primary/secondary cam motor.

one cam is driven off the other.....not a true 4 cam engine

though there are 2 cams per head.....it is not a true 4 cam enginge


there is a master cam and a secondary cam per head.....thats why there is only one cam pulley. if it were a true 4 head cam, there would be 4 cam sprokets. and a timing belt on those requuire the same as our slave setup.
install, 2 full revolutions and recheck.

a toyota 2.2 ...'05 and up reguire the same.

line up marks,install belt,install crank cover, 2 full revolutions, check 0 on crank cover and check for cam marks.

its not rocket science.
the previously posted link shows EXACTLY how to do it.

you can spin the cam pulleys either way. clock or counter clock to realign the marks.

none of the timing marks really matter with the belt off.

its crittical with the belt on.


350 is ok.....360 and beyond the stopping point...not so much.

dont over think it.



set timing marks,install belt, check that everything still lines up, set tensioner. install crank cover, spin motor from carnk bolt 2 revolutions, check to make sure everything lines up.

done.

lex2001

I have a 2001 LS (interference engine) that I changed the belt on last summer. My driver's side cam jumped on me while I was installing the belt. I confirmed with a mechanic that I could rotate it it clockwise (as you are facing the cam) back to it's original location without engine damage. I did that, put the belt on, and it runs like a champ.

"Can I turn the left camshaft pulley clockwise about 350 degree to get the timing mark match?
It is very difficult to turn the left cam pulley counterclockwise now."

So the answer to your question like Emarknot said is yes.

deanbrown

Look, don't confuse me. I don't get this - it jumped clockwise, and then you can turn it all the way round clockwise back to its original position: that is one full 360 rotation clockwise right? So what does it mean its ok to turn it 350 but not 360?

lex2001

You can turn it more than 360. I believe that as long as you don't turn the crankshaft the cams are safe to turn.

deanshark

I gotta put in my .02. Sorry it's a longer post then normal.
The reason noone is listening to you is you are contadicting yourself. In post #3 you say "turn the cam to the mark, oh, and clockwise" Then in post #7 you say "so even if one cam is ahead of the mark say like 10 teeth, you can rotate it counter clockwise to realign" I wish I was here last night b/c this thread got to be outrageous, wow. I really liked the 350 and 360* thing, it already spun at least 10* so another 350 would put it at or past what you call the "damage point". Another reason nobody listen to you is the 7 years you worked for this guy, you have a 4% comeback rate, they don't want thier car to be in that 4%, then they would be out of a car. Personally, I wouldn't take the definate word from someone unless I knew for sure they had a 0% comeback rate, so take a 3 day weekend. These guys are doing this for the 1st time, give 'em a brake. I think they're doing great. And asking questions to learn more, that's awesome. I can't remember my 1st big job, b/c it was over 30 yrs ago, but I know for sure it wasn't easy. Who cares if it takes someone 3 days for this or 4 days for that, as long as it's done, and done right.
Anyway, dashan, the L cam, (drivers side, the actual L cam) it looks like you accidentally spun it clockwise a few teeth, correct? Before you took the belt off you lined up the crank at 50* after TDC, correct? If so, you can spin the L cam counter clockwise backwards to the spot it was before it spun. (how many ever teeth it takes to get back to 50* after TDC) This is why it says to line it up at 50* after TDC, so you have play incase the cams spin.
Anything else, just ask. Keep up the good work and don't get discouraged.

dashan

I pushed the L cam counter clockwise until I met a resistance, then I stopped pushing. I tried the belt. the L cam was still a few teeth pass the L mark on the timing belt.
I was really very tired Yesterday when I made the mistake, and my mind didn't follow me.

deanshark

Well, don't do it when you're tired. When I did mine, the R cam sprung a few teeth when I tried to line up the belt. It was like if I tried to spin it a tiny bit it would jump (like on a spring) a few teeth. So I had to hold it tight to align it. When I spun mine (R cam) counter clocwise there was some resistence to it. But (important note) mine is a 93 NON-interference. Ya might want to check around some more on this b/c Idk if you're supposed to have any, or how much, resistence on yours being an interference engine. I'll tell you, honestly, I'm not 100% sure on how everything works with the interference motor, but most is common sense. Do you have a Lexus or Toyota dealer around you? If so, I would go there and ask to talk to one of thier techs and explain what ya got, you might get your answer right away. You'd be surprised, there's still some nice guys in the world. Although we are getting rare.

dashan

I put the crank pulley back and confirmed that it was indeed at TDC+50 position.

dashan

I got this from Tundra forum
http://www.tundrasolutions.com/forum.../t-205548.html
The Q
dpr64
01-08-2011, 12:48 AM
Say if I were to work on my 2000 V8 Tundra and the timing belt is OFF and the cam marks are mixed up and the crankshaft mark is unknown and not lined up. Could I possibly just align the crankshaft at '0' top dead center (compression or exhaust stroke unknown) and just adjust the cam timing marks so that they now align with the marks, would everything workout okay? Or would I still have to know if the crank was on a compression or exhaust stroke?

Will rotating the crank around a few times or the cams a few times without the belt on damage each other?
The Answer:
kovawa
01-11-2011, 11:44 AM
The white mark on the crank dampener indicates "top dead center" for the number 1 cylinder only. The camshafts position, relative to crankshaft position, determines whether or not the pistons are on their intake, compression, power, or exhaust strokes.Since each piston reaches it's own TDC once per crankshaft revolution, 1 piston out of 8 is at TDC for every 45 degrees of crankshaft rotation. If you need to realign the camshafts to the crank..... be aware that the toyota V8 is an interference engine. Valve damage will occur if you rotate the crank without using caution. The following is the safest way to realign the timing belt without risking major damage to the engine.
1. remove the spark plugs, this step will allow you to turn the engine by hand and let you feel for any piston to valve contact.
2. Gently turn the crank to 22.5 degrees BTDC ( before top dead center ) or ATDC (after top dead center). This position will assure that none of the 8 pistons is at TDC, which reduces the chances of piston to valve contact.
3.Realign the camshaft pullies to the respective timing marks.
4. Rotate the crankshaft back to TDC.
5. Install the timing belt on the engine.
6. Rotate the engine by hand a few times and double check the belt alignment.
7. Reinstall the spark plugs.
Provided that you put everything else back together correctly during the reinstall phase, your engine should run fine.

deanbrown

I wonder why Lexus doesn't recommend we put the crank at TDC+22.5?

deanshark

Those directions are for a 2000 V8. Different engine, vvti?

deanbrown

I guess that with all that tension in the valve springs, its easy for the cam to pop round a bit, but to push it back you would be compressing those springs back in reverse, and that could require quite a force. But I have at least satisfied my own mind that this would be safe, as long as it does not feel like your hitting a wall, and assuming that the manual I have and what a bunch of people here have said is right. That said, I have noticed some glaring mistakes in the service manual, and in this thread.

dashan

I found that it is very difficult to push the L cam pulley counter clockwise, and it is very difficult to push the R cam pulley clockwise. Is the engine designed in this way?

deanbrown

dashan - I am doing this at the same time - the LCam also flipped around clockwise by about 30 degrees, but it seems to turn back by hand all the way with some effort. I had a wire holding one of the spokes to stop it going too far, not sure if it did anything much though. I am on to the water pump now.

dashan

After doing some research and reading advice from members of this forum and of lexus owner club forum, I believe that I am still in good shape and didn't brake anything inside the engine. The Crankshaft pulley STAYED at TDC+50 degree before and after timing belt was off. What I need to do is to push the two cam pulleys and make their timing marks matching the ones on the new belt, respectively. I already put a order on this tool: SCH96800 Camshaft Pulley Holding Tool.